Department of Entomology, Washington State University, 166 FSHN Building, Pullman, WA, 99164, USA.
School of Integrative Plant Science, Plant-Microbe Biology and Plant Pathology Section, Cornell University, Ithaca, NY, USA.
Oecologia. 2021 Aug;196(4):1005-1015. doi: 10.1007/s00442-021-04989-6. Epub 2021 Jul 15.
Herbivores assess predation risk in their environment by identifying visual, chemical, and tactile predator cues. Detection of predator cues can induce risk-avoidance behaviors in herbivores that affect feeding, dispersal, and host selection in ways that minimize mortality and reproductive costs. For herbivores that transmit plant pathogens, including many aphids, changes in herbivore behavior in response to predator cues may also affect pathogen spread. However, few studies have assessed how aphid behavioral responses to different types of predator cues affect pathogen transmission. Here, we conducted greenhouse experiments to assess whether responses of pea aphids (Acyrthosiphon pisum) to predation risk and alarm pheromone (E-β-Farnesene), an aphid alarm signal released in response to predation risk, affected transmission of Pea enation mosaic virus (PEMV). We exposed A. pisum individuals to risk cues, and quantified viral titer in aphids and pea (Pisum sativum) host plants across several time periods. We also assessed how A. pisum responses to risk cues affected aphid nutrition, reproduction, and host selection. We show that exposure to predator cues and alarm pheromone significantly reduced PEMV acquisition and inoculation. Although vectors avoided hosts with predator cues, predator cues did not alter vector reproduction or reduce nutrient acquisition. Overall, these results suggest that non-consumptive effects of predators may indirectly decrease the spread of plant pathogens by altering vector behavior in ways that reduce vector competence and pathogen transmission efficiency.
食草动物通过识别视觉、化学和触觉的捕食者线索来评估其环境中的捕食风险。捕食者线索的检测可以诱导食草动物避免风险的行为，这些行为以最小化死亡率和生殖成本的方式影响食草动物的进食、扩散和宿主选择。对于传播植物病原体的食草动物，包括许多蚜虫，食草动物对捕食者线索的行为反应变化也可能影响病原体的传播。然而，很少有研究评估蚜虫对不同类型的捕食者线索的行为反应如何影响病原体的传播。在这里，我们进行了温室实验，以评估豌豆蚜（Acyrthosiphon pisum）对捕食风险和警报信息素（E-β-法呢烯）的反应——一种蚜虫对捕食风险释放的警报信号——是否会影响豌豆花叶病毒（PEMV）的传播。我们将 A. pisum 个体暴露于风险线索中，并在多个时间点量化蚜虫和豌豆（Pisum sativum）宿主植物中的病毒滴度。我们还评估了 A. pisum 对风险线索的反应如何影响蚜虫的营养、繁殖和宿主选择。我们发现，暴露于捕食者线索和警报信息素显著降低了 PEMV 的获得和接种。尽管传病媒介避免了有捕食者线索的宿主，但捕食者线索并没有改变传病媒介的繁殖或减少营养物质的获取。总的来说，这些结果表明，捕食者的非消耗性影响可能通过改变降低媒介能力和病原体传播效率的方式间接减少植物病原体的传播。
